Manual setting mechanism for digital alarm clock

ABSTRACT

An alarm clock with coaxial digit wheels for 1-minute, 10-minute and hour indications has a pair of contact-carrying disks, rotatable about the same axis, mechanically coupled with the 1minute wheel and with the hour wheel, respectively, for entrainment thereby. Each disk confronts an associated selector drum bearing minute and hour indications, respectively, these disks being independently settable to display the time when the alarm is to ring. Each drum consists of insulating material and carries a terminal of an alarm circuit positioned to engage a contact near the periphery of the associated disk whenever the latter occupies a position corresponding to the selected drum setting; the disks are always conductively interconnected, by a contact spring on one disk engaging a metallic track on the other disk, so that the alarm circuit is completed when both disks occupy their preselected positions. To set the time, the disks are independently steppable by toothed actuators manually reciprocable in a slotted guide plate; a swingable detent interposed between the two lower order digit wheels prevents the resiliently indexable 10-minute wheel from overshooting its next position in response to a too rapid stepping of the 1-minute wheel through the associated disk.

United States Patent Fehrenbacher MANUAL SE'ITING MECHANISM FOR DIGITALALARM CLOCK Wolfgang Fehrenhacher, St. Geor gen, Black Forest, GermanyKUNDO Kieninger &. Obergfell Fabrik fur Technische Laufwerke undApparate, St. Georgen i/Black Forest, Germany Filed: June 10, 1971 Appl.No.: 151,187

Inventor:

Assignee:

Foreign Application Priority Data June 11, 1970 Germany ..P 20 28 679.1

US. Cl ..58/38, 58/19 R, 58/225, 235/1 C, 58/125 C Int. Cl ..G04c 21/00,G04c 21/16 Field of Search....58/38, 19 R, 19 A, 125 R, 125 C,58/I26 R,126 E,22.5,85.5,16 R; 235/] C References Cited UNITED STATES PATENTSPrimary Examiner-Richard B. Wilkinson Assistant Examiner-Stanley A. WalAttorneyKarl F. Ross [57] ABSTRACT An alarm clock with coaxial digitwheels for l-minute, 10-minute and hour indications has a pair ofcontactcarrying disks, rotatable about the same axis, mechanicallycoupled with the l-minute wheel and with the hour wheel, respectively,for entrainment thereby. Each disk confronts an associated selector drumbearing minute and hour indications, respectively, these disks beingindependently settable to display the time when the alarm is to ring.Each drum consists of insulating material and carries a terminal of analarm circuit positioned to engage a contact near the periphery of theassociated disk whenever the latter occupies a position corresponding tothe selected drum setting; the disks are always conductivelyinterconnected, by a contact spring on one disk engaging a metallictrack on the other disk, so that the alarm circuit is completed whenboth disks occupy their preselected positions. To set the time, thedisks are independently steppable by toothed actuators manuallyreciprocable in a slotted guide plate; a swingable detent interposedbetween the two lower order digit wheels prevents the resilientlyindexable 10-minute wheel from overshooting its next position inresponse to a too rapid stepping of the 1-minute wheel through theassociated disk.

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PATENTED I912 3.685.280

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J d {Ross Attorney MANUAL SETTING MECHANISM FOR DIGITAL ALARM CLOCK Mypresent invention relates to a timepiece such as an alarm clock asdisclosed in commonly owned application Ser. No. 101,974 filed by GunterHummel and Erich Scheer 28 December 1970. Such a timepiece may be used,aside from alarm purposes, for timing a photographic exposure, forreading a laboratory instrument, or for carrying out any other operationbeginning and ending at precisely predetermined instants.

More particularly, my invention concerns a preferably electricallydriven timepiece of the digital type, Le. a clock with a set ofoperatively interconnected digit wheels displaying time indications of adifferent denominational orders in a window of a housing, such as theunits and tens digits of the minutes and corresponding numerical valuesfor the hours.

The system disclosed in the aforementioned copending applicationincludes two contact carriers and two rotary selectors coaxiallyjuxtaposed therewith, each selector being independently settable to anyone of a multiplicity of angular positions in which it is retained byfriction or by suitable indexing means. The two contact carriers, whichare preferably disk-shaped and will be referred to hereinafter as disks,are positively linked with the lowest ranking and a higher ranking digitwheel of the display unit, respectively, generally the 1- minute wheeland the hour wheel. As the rate of rotation of the disk entrained by thehour wheel is an aliquot fraction of the rate of rotation of the diskentrained by the 1-minute wheel, the latter will perform several(usually 12 or 24) full revolutions per operating cycle while the formermakes only one turn in the course of such cycle. Only once per cycle,therefore, will the two disks simultaneously occupy predeterminedpositions relative to the associated selectors in which coactingcontacts on the two disks and the two selectors establish a connectionto complete an external load circuit including, for example, an alarmdevice. The time of occurrence of such a relative position depends, ofcourse, on the presetting given to the two selectors which areadvantageously calibrated in minutes and hours, respectively. Thus, thealarm will go off at exactly the instant when the hour and minutesettings of the selectors match the digital reading of the clockwork,the circuit being broken as soon as the parts move out of that relativeposition. If the clockwork is conventionally stepped so that its readingchanges only once per minute, the coincidence position and therefore theoperation of the alarm will last for exactly 1 minute. Such a steppingdrive, causing successive jumps of each digit wheel or reel by onedivision, is well known in decimal counters or registers; it may includea single tooth on an input member periodically engaging the gear coupledwith the digit wheel, a stepping pawl controlled by an electronicallypulsed balancer, or a Geneva movement.

While for alarm clocks it will generally be sufficient to span a periodnot greater than 24 hours, this period could evidently be extended to,say, a week or a month by a modification of the time base of thecontrolling digit wheels and/or by the inclusion of a further selectorand disk in series with the two mentioned above, this further disk beingentrained by a digit wheel of still higher denominational ordercounting, for example, the number of days.

ln order to facilitate mass production of the parts, the two carrierdisks advantageously are of identical basic construction including eacha body of dielectric material with conductive facings on oppositesurfaces and with throughgoing metallic connectors therebetween; one ofthe facings of each disk, on the side remote from the other disk, formspart of a contact spring projecting axially toward the associatedselector which also has an insulating body formed with a peripherallylocated discontinuity in its insulation, the contact spring engagingthis discontinuity once per revolution to extend the circuit. Thediscontinuity may be simply a hole through which a contact spring canreach an underlying conductive surface, but in a preferred constructionit is constituted by a metallic rivet with a first head contacting sucha surface and a second head engageable by the contact spring of thedisk. The metallic facings on the two confronting disk sides aredesigned to provide a permanent conductive connection between the disks,one of these facings having the shape of an annular track while theother facing forms a contact spring engaging that track in any relativeposition of the two disks.

The general object of my present invention is to provide simple andconveniently operable means for manually advancing the several digitwheels for altering their time indications, more particularly forseparately setting their minute and hour readings, independently of theassociated electric motor or other prime mover serving for theirautomatic displacement.

A more specific object is to provide a compact assembly of manualcontrollers for the adjustment of both the digit wheels and theassociated contact carriers to set the time and to select the desiredalarm position, these controllers being readily accessible withoutrequiring the opening of the clock housing or the removal of any parts.

In accordance with the instant improvement, I provide separate steppingmeans respectively engageable with the two contact carriers forselectively advancing same together with the associated digit wheels,advantageously against the force of indexing means yieldably retainingeach digit wheel in any one of its several indicating positions, bypreferably one indicating position at a time. Thus, the hour wheel maybe stepped in increments of either 15 or 30 whereas the 1-minute wheel,entraining the 10-minute wheel can be rotated through 36 with everystroke of the associated stepper. These steppers, according to a moreparticular feature of my invention, are designed as a pair of slidersreciprocably guided in a slotted plate and provided with workingformations, such as sets of sawteeth, positioned to engage the toothedperipheries of a pair of rotary bodies respectively coupled with the twocontact carriers for joint rotation. While these rotary bodies could beintegral with the two carrier disks, it is generally more convenient todesign them as pinions of substantially smaller diameter meshingdirectly or indirectly with the tooth peripheries of these disks.

In order to enable unidirectional stepping of each carrier disk, eachslider is advantageously made of two interfitted parts, one of themresting against a surface of the slotted guide plate whereas the othercarries the sawteeth and is movable relatively to the first-mentionedpart, in a direction transverse to the plate surface, against thebiasing force of a spring (preferably a curved leaf spring) during thereturn of the slider from its offnnormal to its normal position.

With the 1-minute wheel driven (preferably stepwise) by the prime mover,motion is transmitted from it through the IO-minute wheel to the hourwheel with the aid of coacting projections on confronting sides of theseveral digit wheels. Advantageously, the interdigital transmissionstages are recessed in concave sides of the coaxial, equal-diarneterl-minute and hour wheels, with the smaller IO-minute wheel centered onan axis parallel to the common axis of the two larger wheels and withthe distance between these axes approximately equaling the difference ofthe wheel radii whereby the digit-carrying peripheral portions of thesewheels lie substantially in a common plane within the display zoneexposed by a window in the clock housing. As the coacting lateralprojections of the digit wheels move in orbits which coincide only inthe vicinity of this common plane, each higher order wheel is entrainedby the immediately preceding lower order wheel only once per revolutionof the latter and over a fraction of a circle. Nevertheless, if the1-minute wheel is manually stepped at high speed in the couplingposition of the two minute wheels, the 10-minute wheel could be impelledwith excessive force so as to skip its next indexed indicating position.To avoid such overstepping, I prefer to interpose between the two minutewheels a pivoted stop member which is normally biased into a blockingposition in the path of the several entrainable projections of thelO-minute wheel but is momentarily deflected into a nonblockingposition, by the driving prohection of the 1-minute wheel, at theinstant of operative coupling of the two minute wheels.

Since it may be necessary at times to advance the hour wheel withoutconcurrently rotating the minute wheel, the driving projection of the10-minute wheel (on the side thereof confronting the hour wheel) isadvantageously designed as an overrunning-clutch type coupler by beingmounted on a spring-loaded lever, giving clearance to the lateralprojections of the hour wheel upon reversal of the normal relativerotation of the two wheels.

The above and other features of my invention will be described in detailhereinafter with reference to the accompanying drawing in which:

FIG. 1 is a front-elevational view (with parts broken away) of a digitalclockwork provided with an alarm mechanism according to my invention;

FIG. 2 is a bottom view of the assembly of FIG. 1;

FIG. 3 is an enlarged sectional elevation of the alarm control stage ofthe assembly of FIGS. 1 and 2;

FIG. 4 is a side view of the assembly of FIG. 3;

FIG. 5 is a bottom view of that assembly;

FIG. 6 is an exploded perspective view of the digit wheels andassociated couplings of the clockwork of FIGS. 1 and 2;

FIG. 7 is a side view of an intermediate digit wheel, as seen in thedirection VII of FIG. 6;

FIG. 8 is an enlarged bottom view of a component also seen in FIG. 5;

FIG. 9 is a side view of a slider forming part of the component of FIG.8;

FIG. 10 shows the component of FIG. 8 from the opposite side; and

FIG. 11 is a view similar to FIG. 9 but showing the component in sectionand on a larger scale.

In FIGS. 1 and 2 I have shown parts of the housing of an electricaldigital clock including a bracket 1 with two upstanding anns 2, 3. Thishousing has a window, not shown, for displaying the time of day (here16:36 hours or 4:36 PM) in the form of digits carried by three coaxialwheels 4, 5 and 6. Digit wheel 4, bearing the numerals 0 to 9, and digitwheel 5, bearing the numerals 0 to 5, show the minutes; digit wheel 6displays the hours with the aid of eight peripherally mounted prismaticbodies of which three, designated 8, 9 and 10, are visible in FIG. 1.These bodies are in the form of regular three-sided pyramids provided,as shown in the copending application referred to, with star wheels eachcarrying three angularly spaced pins engageable by a fixed stud in astationary end cap ll secured to arm 2. Reference in this connection mayalso be made to commonly owned application Ser. No. 32,660 filed Apr.28, 1970 by Oskar Obergfell and Giinter Hummel. now US. Pat. No.3,616,642. Thus, during any revolution of wheel 6, any digit carrier 8,9, 10 etc. is tripped on passing through its nadir position and rotatedthrough to exhibit a new face to the observer; these faces, 24 in all,carry the numerical designations from O0 to 23. Naturally, the 24 hourreadings could also be designated 1 AM to 12 AM and 1 PM to 12 PM. Eachdigit carrier may be held in its position relative to wheel 6, for afull revolution of that wheel, by friction or with the aid of indexingmeans not shown.

Bracket 1 supports, via posts 13 and screws 14, a similar, smallerbracket 15 having upstanding arms 16 and 17. The arm 3 of bracket 1 isbroadened to serve as a mounting plate for a motor 22 and other parts ofthe stepping drive, the motor having a base 31 supported on plate 3 byposts 21. Two further mounting plates 33, 34 are secured to plate 3 bymeans of mounting bolts 32 surrounded by tubular spacers 35.

Mounting plates 33 and 34 define a compartment for a unit, more fullyillustrated in FIG. 3, which controls the closure of an alarm circuitincluding a power source 201, a bell or buzzer 202, and a manual circuitbreaker 203 assumed to be closed. This circuit is connected across apair of binding posts 55, 55' fixedly held in mounting plates 33 and 34,respectively. These mounting plates are provided with a pair of fixedcoaxial sleeves 41, 42 which receive gudgeons 43, 44 of an axle 40 andwhich carry a pair of fixed but resiliently deformable indexing plates49, S0 of insulating material provided on their confronting surfaceswith conductive annular zones 51, 51'. The sleeves 41 and 42 furtherreceive hubs 45, 46 of a pair of insulating selector elements 37 and 36,respectively, which are generally cup-shaped with outwardly facingconcavities embracing the indexing plates 49 and 50. The elements 37 and36, which will be referred to hereinafter as drums, have end walls 53,54 each formed near its periphery with an annular array of corrugations56, 56' engaged by the rounded extremity 57 or 57' of the associatedbinding post 55 or 55', the latter being secured to the correspondingindexing plate 49, 50 whose resiliency tends to maintain the extremities57 or 57 in engagement with the corrugated surface 56 or 56'. Thecorrugations of this surface are as numerous as the angular settings ofthe corresponding selector drum,

namely 24 in the case of the hour drum 36 and 60 in the case of theminute drum 37. To facilitate the manual setting of either drum, theirouter peripheries are provided with gear teeth 60 and 61. Posts 55 and55' are in conductive contact with the metalized zones 51 and 51 ofplates 49 and 50, respectively, which are engaged by proximal heads ofrivets 52, 52 traversing the drum walls 53 and 54, respectively.

As illustrated in FIG. 3, the outer surface of drum 37 carries hourmarkings (here ranging from O0 to 23, in conformity with those of digitwheel 6) while drum 36 is similarly provided with minute markings(ranging from O0 to 59). It will be convenient, as shown, to write outonly the even-numbered indications and to replace the odd-numbered onesby lines, dots or the like. These 24 scale divisions of drum 37 and 60scale divisions of drum 36 can be observed through a viewing slot of thehousing and/or read against an arrow or other marker alongside each drumshowing the exact hour and minute to which the two drums have been set.

Two disks 38, 39 are sandwiched between the drums 36, 37 and are alsofreely rotatable on the axle 40. The two disks have identically shapedbodies of insulating material, preferably a thermoplastic resin, and arerespectively coupled with l-minute wheel 4 and with hour wheel 6 forentrainment thereby. Thus, disk 38 performs exactly one revolution perhour whereas disk 39 makes one revolution every 24 hours. The latterdisk, juxtaposed with drum 37, carries a contact spring 79 bearing uponthe outer surface of drum wall 53 along an orbit which includes therivet 52 so that the electric circuit from terminal 55 is extended todisk 39 whenever this disk and the drum 37 are in a predeterminedrelative position, i.e. the position in which the hour reading of thedrum corresponds to that displayed by the digit carriers 8 etc. of wheel6. In an analogous manner, disk 38 carries a contact spring 81 on itsside facing the drum 36, the latter spring bearing upon the outersurface of drum wall 54 to make contact with the rivet 52' thereof in arelative position in which the minute reading of the drum corresponds tothat displayed by the digit wheels 4 and 5. Rivet 52 and spring 79 areso dimensioned and positioned that their area of contact extends overless than and is limited to a single operating position of disk 39 forany indexed position of drum 37; in an analogous manner, the area ofcontact of rivet 52 and spring 81 extends over less than 6 and is alsolimited to a single operating position of disk 38 for any indexedposition of drum 36. Disk 39 is further provided with a conductiveannular track 83 continually wiped by a contact brush 80 on the innersurface of disk 38; with springs 80 and 81 conductively interconnectedand with spring 79 also permanently connected to track 83, spring 79lies always in circuit with spring 81 so that the load circuit 201 203is completed whenever spring 79 contacts the rivet 52 at the same timethat the spring 81 engages the rivet 52'.

The rivets 52 and 52 represent discontinuities in the insulation oftheir respective drums and, in a simplified system, may be replaced byopenings in the drum wall through which the free ends of the contactsprings 79 and 81 can reach the conductive zones 51 and 51',respectively, whenever the disk position matches the settings of theassociated drums. Such a simplification, reducing the contactresistance, is particularly advantageous with low-voltage powersupplies, yet the interposition of the rivets affords greater precision.

The transmission linking digit wheels 4 and 6 with disks 38 and 39,respectively, includes a shaft 66 extending parallel to the wheel axis,this shaft being journaled in an upturned extension 68 of bracket 1 andin the mounting plate 33. A gear on shaft 66 is in mesh with the toothedperiphery of wheel 6 while a pinion 69 on the other end of that shaftdrives a gear 77 keyed, together with a pinion 78, on a sleeve 76 freelyrotatable on another shaft 73 spanning the plates 33 and 34. A similarsleeve 70, freely rotatable on shaft 66, bears a gear 71 in mesh withthe toothed periphery 64 of wheel 4 and terminate in a pinion 72meshingwith a gear 74 keyed to shaft 73. Disk 39 has a toothed periphery62 in mesh with pinion 78 whereas disk 38 also has a toothed periphery63 in mesh with a similar pinion keyed to shaft 73. This gear trainprovides a step-down ratio of 24 m (i.e. 3 1 for the torque transmissionfrom wheel 6 to disk 39, the latter being thus stepped once per hourthrough an angle of 15, and provides a step-down ratio of 6 1 betweenwheel 4 and disk 38 whereby this disk is advanced every minute throughan angle of 6. Thus, the load circuit of FIG. 3 is closed once per24-hour period for exactly 1 minute; naturally, this load circuit mayinclude a holding relay or other timing means for either foreshorteningor exte nding the operating time of the alarm 202.

The positive coupling of the digit wheels 4 and 6 with the disks 38 and39, respectively, via transmission 66 79 translates any manualadjustment of these disks into a corresponding displacement of thecorresponding wheels. The means for making this adjustment, as well asthe interstage coupling mechanism for converting the periodic steppingof wheel 4 by motor 22 (at 1- minute intervals) into less frequentadvances of wheels 5 and 6, will be described hereinafter with referenceto FIGS. 4 11.

Digit wheels 4, 5 and 6 are rotatably joumaled on three fixed shafts 19,18 and 7, respectively, all parallel to the transmission shaft 66. Shaft7 extends between uprights 2 and 16; shafi 18 spans the arms 16 and 17of bracket 15 which lie within the concave sides of the two hollowwheels 6 and 4, confronting the intermediate wheel 5, while shaft 19 issecured to uprights 17 and 3 in line with shaft 7. The two alignedshafts 7 and 19 are offset from shaft 19 by a distance equal to thedifference between the radii of the two larger wheels 4, 6 (which are oflike diameter) and of the smaller wheel 5 whereby the centrally disposedfaces of the polygonal peripheries of the wheels 4, 5 and 6 as viewed inH6. 1 (constituted in the case of wheel 6 by an exposed prism face suchas that of prism 9) are coplanar in their display position. Since thenumber of faces of wheels 4 and 5 are 10 and six, respectively, theratio of their radii is approximately 5:3; this afi'ords sufficientclearance to accommodate the bight portion of bracket 15 adjacent wheel5 within the confines of wheels 4 and 6.

Wheel 5 is also laterally recessed, as seen in FIGS. 6 and 7, so as tohave two overhanging rims 111, 136 corresponding to a rim on the concaveside of wheel 6 and a similar rim on the confronting face of wheel 4.The spaces framed by rim 100 of wheel 6 and by the corresponding rim ofwheel 4 serve to accommodate indexing means constituted, in the case ofwheel 6, by a ratchet 101 normally engaged by a pawl 103 which isswingable about a fulcrum 104 and has its free end 105 stressed by atension spring 107 anchored at 106 to the body 102 of the digit wheel.The analogous indexing mechanism for wheel 4 has not been illustrated,yet its counterpart on wheel 5 has been shown in FIG. 7 to comprise aratchet 117 rigid with shaft 18 and a pawl 121 pivoted to the wheel at119, its free end 120 being stressed by a spring 116 anchored at 115 toan escapement lever 1 13 with a fulcrum 1 12. The free end 1 14 of lever113 is integral with an axially extending projection or dog 110, havinga transverse face 119 and a beveled face 120, which is normally held byspring 116 against the inner peripheral surface of rim 111 so as to liein the path of a set of co-operating projections 109 of wheel 6 formedas internal ribs on the rim 100 thereof. Similar projections 130, in theshape of prismatic studs, extend axially from the inner periphery of rim136 of wheel 5 into the concave side of wheel 4 for coupling engagementwith a single dog 131 fixed within that side to the rim of the latterwheel. In conformity with the number of active faces of wheels 5 and 6,ratchets 117 and 101 have six and eight teeth, respectively; similarly,there are eight projections 109 on the former wheel and six projections130 on the latter wheel.

Thus, in view of the relative eccentricity of the orbits of projections130, 131 and 109, 110, wheel 5 is stepped once per revolution of wheel 4through an angle of 60 whereas the wheel 6 is advanced once perrevolution of wheel 5 through an angle of 45. The primary stepping drivefor wheel 4 includes, besides the synchronous motor 22, a gear train23-30, 30;, 30b; if this drive comprises a stage with positionimmobilization of the load, such as a Geneva motion, the aforementionedindexing mechanism for digit wheel 4 may be omitted.

The presence of lever 113 has the effect of an overrunning clutch bypermitting the hour wheel 6 to overtake the IO-minute wheel 5 on beingmanually rotated (counterclockwise as viewed in FIG. 7) to change thehour indication, with the projections 109 camming aside the projection110 by bearing upon the beveled face 120 thereof if the latterprojection happens to lie between the two foremost ribs 109', 109" ofwheel 6 as illustrated in FIG. 6, i.e. if wheel 5 occupies the 50-minute position in which its next step would advance the wheel 6 from,say, the l l-oclock to the l2-oclock position.

Thus, regardless of the relative positions of the several couplingprojections, the positions of the two minute wheels 4 and 5 will remainunaffected by any adjustment of hour wheel 6 so as to eliminate the needfor any subsequent readjustment of the minute indications. On the otherhand, a manual advance of 1- minute wheel 4 may also step the lO-minutewheel 5 and possibly the hour wheel 6, in the same way as does theautomatic drive.

In view of the play afforded by the indexing mean 117, 118 and 101, 103,the range of positive entrainment of wheel 5 by wheel 4 and of wheel 6by wheel 5 may be somewhat less than 60 and 45, respectively, inasmuchas the force of loading springs 116 or 107 will in such case completethe rotation of the follower wheel through the desired angle. If,however, the user applies excessive force to the l-minute wheel 4 inturning it past the carry position (illustrated in FIG. 6) in which dog131 engages the next projection of wheel 5, the latter could bepropelled past its next indexing position so as to overshoot its desiredsetting. To prevent this, I prefer to interpose between the wheels 4 and5 a stop member 132 in the form of a yoke with two arms 133, 134straddling the shaft 18 of wheel 5, this yoke having a hole 132traversed by a pivot pin (not shown) in the recessed side of wheel 4 soas to be limitedly swingable between an operative position and aninoperative position. In its operative position, into which the yoke 132is urged by a spring 137 anchored to it at 138 and tied to the body ofwheel 4 at 139, an axial extension 141 of arm 133 lies in the path of astud 130' so as to block the advance of the wheel 5; a transverseextension 140 of arm 134 lies in a zone beyond the ends of studs 130. Asthe dog 131 approaches the stud 130" to be entrained, it engages theextension 140 so as to deflect the yoke 132 in a clockwise sense into anon-blocking position to clear the stud 130', yoke 132 returningimmediately to its normal position with the continuing advance of dog131 so that extension 141 intercepts the next-following stud of wheel 5at a point where pawl 121 is effective to index that wheel for a propercentering of its exposed digit in the viewing window. This positivelimitation of the advance of intermediate wheel 5 to a single step alsoprevents any possible overstepping of hour wheel 6. An abutment 142integral with bracket arm 17 arrests the stamped or molded yoke member132 in its normal position by engaging its arm 133.

FIGS. 4, 5 and 8 11 show details of the manual stepping means for wheels4 and 6. A guide plate with a pair of parallel slots 156, 156',transverse to the wheel axes, is secured to mounting plates 33, 34 withthe aid of indentations 151, 151' and slots 152, 152' of plate 150receiving projections 188, 188' and tabs 187, 187' of these mountingplates, two hook-shaped lugs 186, 186' on the latter plates engagingedges 184, 184' of recesses 185, 185' formed at the lower comers ofplate 150 as viewed in FIGS. 8 and 10 (see also FIG. 2). Two sliders155, are respectively guided in slots 156, 156' for manualreciprocation, each of these sliders consisting (as particularlyillustrated for slider 155) of an outer part 153 and an inner part 154snapfitted together. As best seen in FIG. 11, part 153 has a T-profilewith a stem 162 and a bar 159 having a milled surface 160, T-bar 159being constituted by a raised portion of a strip 158 which rests flatagainst the outer surface of guide plate 150 and spans the slot 156thereof; corresponding elements of slider 155' have been designated158', 159'. Stem 162 is formed with a pair of bosses 165 received, withplay, in recesses of two jaws 164 of part 154 bracketing that stem, part154 being of sufficiently resilient material (metal or plastic) tofacilitate the snap interfitting of the two parts within a cutout ofstrip 158. Jaws 164, passing together with stem 162 through guide slot156, form a web integral with a flange of part 154 projecting laterallybeyond that slot, this flange being formed with sawteeth 163 positionedto engage a set of peripheral teeth of sleeve 76 integral with pinion 78(cf. FIG. 2); the corresponding sawteeth of slider 155' are engageablewith similar teeth 174 on an extension of pinion 75. A curved leafspring 173, also bridging the slot 156, has a central slot traversed bythe web 164 so as to bear upon the flange portion of part 154 in aninward direction (arrow A, FIG. 11), i.e. in a sense tending to reducethe clearance 161 between web 164 and T-bar 159 so as to hold thesawteeth 163 in line with the coacting teeth 175, these latter teethbeing advantageously undercut as shown in order to maintain theirengagement with teeth 163 when the slider 155 is moved upwardly in thedirection of arrow B. Upon the subsequent return stroke, the slopingedges of teeth 163 and 175 drive the part 154 outwardly against theforce of spring 173 into the position shown in FIG. 1 1 (which, however,will not normally exist once the slider has cleared the pinion 76 onreturning to its rest position against the direction of arrow B).Reverse rotation of pinions 75, 78 is prevented by friction and by theaforedescribed indexing means, supplemented if necessary by apawl-andratchet arrangement (e.g. a modification of indexing elements101, 103 and 117, 118) permitting only unidirectional movement of thedisks 62, 63 and the digit wheels 4 6 coupled therewith.

Sliders 155 and 155' are biased into their normal retracted positions(i.e. downwardly in FIGS. 8 11) by a transverse arm 167 whoseextremities 168, 168' engage in a clearance 169 formed between the twoparts of the respective slider. 'I'he midpoint 171 of arm 167 is undertension from a coil spring 166 lodged in a cutout 170 of guide plate 150and anchored to the lower edge 172 of that cutout; either slider maytherefore be moved upwardly, with the limits of the corresponding guideslot 156 or 156', against the restoring force of that spring. The lengthof these slots is advantageously so chosen that a stroke of the slider155 rotates disk 39 and hour wheel 6 through a little more than whereasthe slider 155' rotates disk 38 and 1- minute wheel 4 through a littlemore than 6 (as indicated by the somewhat greater length of slot 156 incomparison with slot 156'), enabling each digit wheel to be returned toits proper indexed position by the associated spring'loaded pawl. Thus,the number of manual reciprocations of sliders 155 and 155' determinesthe number of hours and minutes, respectively, by which the time settingof the clock is to be advanced.

To adjust the alarm position, a pair of milled wheels 176, 177 arefreely rotatable on a shaft 178 spanning the mounting plates 33 and 34.Wheels 176 and 177 are inegral with a pair of pinions 1'79, 180,respectively, meshing with respective pinions 182, 183 on another shaft181 supported by these plates. Pinions 182 and 183 engage the peripheralteeth 61 and 60, respectively, of drums 36 and 37 which are thusindependently rotatable with the aid of these milled wheels. With guideplate 150 mounted at the bottom of the clock frame and the nadirs ofwheels 176, 177 coplanar with the milled surfaces of bars 159, 159', andwith the center of gravity of the clock mechanism located above therectangle defined by these four elements, 176, 177, 159, 159, the lattermay serve as supporting legs for the timepiece.

The system herein disclosed allows for manual resetting at any time,even during the stepping of a higher order digit wheel by one of a lowerorder.

lclaim:

1. A timepiece comprising:

a set of operatively interconnected digit wheels including a first wheelprovided with time indications of a relatively high denominational orderand a second wheel provided with time indications of a relatively lowdenominational order;

drive means for rotating said first wheel at a relatively slow rate andsaid second wheel at a relatively fast rate;

a first contact carrier and a second contact carrier juxtaposed forindependent rotation about a common axis;

transmission means positively linking said first and second contactcarriers with said first and second wheels, respectively, for rotaryentrainment thereby;

first and second stepping means normally disengaged from butrespectively engageable with said first and second contact carriers forselectively advancing same together with the associated digit wheelsindependently of said drive means;

a first rotary selector and a second rotary selector centered on saidaxis and confronting said first and second contact carriers,respectively, said selectors being independently settable to any one ofa multiplicity of angular positions;

retaining means for holding each of said selectors in a chosen angularposition;

co-operating first contacts on said first contact carrier and said firstselector making in a predetermined relative position thereof;

co-operating second contacts on said second contact carrier and saidsecond selector making in a predetermined relative position thereof;

conductor means maintaining a continuous conductive connection betweenthe contacts on said contact carriers; and

a load circuit including a source of current and a controlled deviceconnected across the contacts of said selectors for actuation of saiddevice upon simultaneous making of said first and second contacts.

2. A timepiece as defined in claim 1 wherein said drive means comprisesmechanism for intermittently advancing said first and second wheelsthrough successive indicating positions corresponding to themultiplicity of angular positions of said first and second selectormeans, respectively, whereby said load circuit remains closed for aperiod equaling the residence time of said second wheel in any of itsindicating positions, each of said digit wheels being provided withindexing means for yieldably retaining same in each indicating positionthereof, said stepping means being operable to advance the associateddigit wheels by one indicating position.

3. A timepiece as defined in claim 2 wherein said contact carriers areprovided with a pair of peripherally toothed rotary bodies respectivelycoupled therewith for joint rotation, said first and second steppingmeans comprising each a reciprocably guided slider with a workingformation positioned to engage the toothed periphery of the associatedrotary body for unidirectionally entraining same upon reciprocationbetween a normal and an off-normal position.

4, A timepiece as defined in claim 3 wherein said transmission means isprovided with a fixed frame,

further comprising a guide plate on said frame having a pair of slotsrespectively accommodating said sliders.

5. A timepiece as defined in claim 4 wherein each of said sliderscomprises two interfitted parts, one of said parts resting against asurface of said guide plate, the other of said parts having a set ofsawteeth constituting said working formation and being movable withreference to said one of said parts, in a direction transverse to saidsurface, against a biasing force for clearing the toothed periphery ofthe associated rotary body upon a return of the slider to said normalposition.

6. A timepiece as defined in claim 5 wherein said other of said partshas a web traversing the corresponding slot of said guide plate and aflange rigid with said web extending laterally beyond said correspondingslot, said web bearing said sawteeth, each slider being further providedwith spring means bearing upon said web and said guide plate alongsidesaid corresponding slot to generate said biasing force.

7. A timepiece as defined in claim 6 wherein said one of said parts hasa stem inside said corresponding slot and said web comprises two jawsbracketing said stem, said jaws and said stem being provided withinterengaging retaining means.

8. A timepiece as defined in claim 7 wherein said one of said parts isformed with a milled ridge carrying said stem.

9. A timepiece as defined in claim 5 wherein said rotary bodies haveundercut peripheral teeth engageable by said sawteeth.

10. A timepiece as defined in claim 4 wherein said sliders are providedwith resilient restoring means anchored to said plate for tending tomaintain each slider in said normal position.

11. A timepiece as defined in claim 10 wherein said slots are parallelto each other, said restoring means comprising an arm generallyperpendicular to said slots having opposite extremities in engagementwith said sliders and a tension spring attached to a midpoint of saidarm.

12. A timepiece as defined in claim 3 wherein said contact carriers aretwo peripherally toothed disks, said rotary bodies being a pair ofpinions respectively meshing with said disks.

13. A timepiece as defined in claim 2 wherein said first and secondwheels are of like diameter and centered on said common axis, said digitwheels including a third wheel of smaller diameter centered on a furtheraxis offset from said common axis and interposed between said first andsecond wheels, said third wheel being provided with time indications ofan intermediate denominational order, the time indications of all digitwheels being displayed on peripheral portions thereof lyingsubstantially in a common plane parallel to said common and furtheraxes, said mechanism including a prime mover for said first wheel andcoacting projections on confronting sides of said first, third andsecond wheels intermittently engageable with one another in the vicinityof said common plane.

14. A timepiece as defined in claim 13 wherein said first and secondwheels are provided with concave sides facing said third wheel andreceiving said coacting projections thereof.

15. A timepiece as defined in claim 14 wherein said tran mission me s isrovided wi a f e frame including an outer rack t spanning a ll sai igitwheels and an inner bracket on said outer bracket received partly insaid concave sides and spanning said third wheel, said digit wheelsbeing provided with fixed axles secured to adjoining arms of said innerand outer brackets, said indexing means including co-operating memberson said axles and on said wheels.

16. A timepiece as defined in claim 15 wherein said third wheel isprovided, on its side confronting said first wheel, with a levercarrying one of said projections and with biasing means normally holdingsaid lever in a position for periodically advancing said first wheel butenabling manual rotation of said first wheel independently of said thirdwheel under the control of said first stepping means.

17. A timepiece as defined in claim 16 wherein said co-operating membersinclude a pawl on the side of said third wheel confronting said firstwheel, said biasing means comprising a spring anchored to both saidlever and said pawl.

18. A timepiece as defined in claim 15, further comprising stop meanspivoted on said inner bracket in the concave side of said second wheelfacing said third wheel and resilient means normally holding said stopmeans in the path of several projections present on the confronting sideof said third wheel for preventing the latter from substantiallyovershooting an indexed indicating position thereof, a coactingprojection in the concave side of said second wheel being engageablewith said stop means for momentarily deactivating same upon engagementwith any of said several projections to permit the advance of said thirdwheel.

19. A timepiece as defined in claim 1 wherein said selectors are a pairof peripherally toothed drums, said transmission means being providedwith a frame supporting said stepping means, further comprising a shafton said frame parallel to said axis, a pair of setting wheels for saidselectors independently rotatable on said shaft, and gear meanspositively coupling said setting wheels with said drums.

20. A timepiece as defined in claim 19 wherein said first and secondstepping means are a pair of sliders reciprocably guided in said framefor parallel motion transverse to said axis, said sliders and saidsetting wheels projecting from the underside of said frame atspaced-apart locations in coplanar relationship to form a set ofsupporting legs therefor.

1. A timepiece comprising: a set of operatively interconnected digitwheels including a first wheel provided with time indications of arelatively high denominational order and a second wheel provided withtime indications of a relatively low denominational order; drive meansfor rotating said first wheel at a relatively slow rate and said secondwheel at a relatively fast rate; a first contact carrier and a secondcontact carrier juxtaposed for independent rotation about a common axis;transmission means positively linking said first and second contactcarriers with said first and second wheels, respectively, for rotaryentrainment thereby; first and second stepping means normally disengagedfrom but respectively engageable with said first and second contactcarriers for selectively advancing same together with the associateddigit wheels independently of said drive means; a first rotary selectorand a second rotary selector centered on said axis and confronting saidfirst and second contact carriers, respectively, said selectors beingindependently settable to any one of a multiplicity of angularpositions; retaining means for holding each of said selectors in achosen angular position; co-operating first contacts on said firstcontact carrier and said first selector making in a predeterminedrelative position thereof; co-operating second contacts on said secondcontact carrier and said second selector making in a predeterminedrelative position thereof; conductor means maintaining a continuousconductive connection between the contacts on said contact carriers; anda load circuit including a source of current and a controlled deviceconnected across the contacts of said selectors for actuation of saiddevice upon simultaneous making of said first and second contacts.
 2. Atimepiece as defined in claim 1 wherein said drive means comprisesmechanism for intermittently advancing said first and second wheelsthrough successive indicating positions corresponding to themultiplicity of angular positions of said first and second selectormeans, respectively, whereby said load circuit remains closed for aperiod equaling the residence time of said second wheel in any of itsindicating positions, each of said digit wheels being provided withindexing means for yieldably retaining same in each indicating positionthereof, said stepping means being operable to advance the associateddigit wheels by one indicating position.
 3. A tiMepiece as defined inclaim 2 wherein said contact carriers are provided with a pair ofperipherally toothed rotary bodies respectively coupled therewith forjoint rotation, said first and second stepping means comprising each areciprocably guided slider with a working formation positioned to engagethe toothed periphery of the associated rotary body for unidirectionallyentraining same upon reciprocation between a normal and an off-normalposition.
 4. A timepiece as defined in claim 3 wherein said transmissionmeans is provided with a fixed frame, further comprising a guide plateon said frame having a pair of slots respectively accommodating saidsliders.
 5. A timepiece as defined in claim 4 wherein each of saidsliders comprises two interfitted parts, one of said parts restingagainst a surface of said guide plate, the other of said parts having aset of sawteeth constituting said working formation and being movablewith reference to said one of said parts, in a direction transverse tosaid surface, against a biasing force for clearing the toothed peripheryof the associated rotary body upon a return of the slider to said normalposition.
 6. A timepiece as defined in claim 5 wherein said other ofsaid parts has a web traversing the corresponding slot of said guideplate and a flange rigid with said web extending laterally beyond saidcorresponding slot, said web bearing said sawteeth, each slider beingfurther provided with spring means bearing upon said web and said guideplate alongside said corresponding slot to generate said biasing force.7. A timepiece as defined in claim 6 wherein said one of said parts hasa stem inside said corresponding slot and said web comprises two jawsbracketing said stem, said jaws and said stem being provided withinterengaging retaining means.
 8. A timepiece as defined in claim 7wherein said one of said parts is formed with a milled ridge carryingsaid stem.
 9. A timepiece as defined in claim 5 wherein said rotarybodies have undercut peripheral teeth engageable by said sawteeth.
 10. Atimepiece as defined in claim 4 wherein said sliders are provided withresilient restoring means anchored to said plate for tending to maintaineach slider in said normal position.
 11. A timepiece as defined in claim10 wherein said slots are parallel to each other, said restoring meanscomprising an arm generally perpendicular to said slots having oppositeextremities in engagement with said sliders and a tension springattached to a midpoint of said arm.
 12. A timepiece as defined in claim3 wherein said contact carriers are two peripherally toothed disks, saidrotary bodies being a pair of pinions respectively meshing with saiddisks.
 13. A timepiece as defined in claim 2 wherein said first andsecond wheels are of like diameter and centered on said common axis,said digit wheels including a third wheel of smaller diameter centeredon a further axis offset from said common axis and interposed betweensaid first and second wheels, said third wheel being provided with timeindications of an intermediate denominational order, the timeindications of all digit wheels being displayed on peripheral portionsthereof lying substantially in a common plane parallel to said commonand further axes, said mechanism including a prime mover for said firstwheel and coacting projections on confronting sides of said first, thirdand second wheels intermittently engageable with one another in thevicinity of said common plane.
 14. A timepiece as defined in claim 13wherein said first and second wheels are provided with concave sidesfacing said third wheel and receiving said coacting projections thereof.15. A timepiece as defined in claim 14 wherein said transmission meansis provided with a fixed frame including an outer bracket spanning allsaid digit wheels and an inner bracket on said outer bracket receivedpartly in said concave sides and spanning said third wheel, said digitwheels being provided with fixed axles secured to adJoining arms of saidinner and outer brackets, said indexing means including co-operatingmembers on said axles and on said wheels.
 16. A timepiece as defined inclaim 15 wherein said third wheel is provided, on its side confrontingsaid first wheel, with a lever carrying one of said projections and withbiasing means normally holding said lever in a position for periodicallyadvancing said first wheel but enabling manual rotation of said firstwheel independently of said third wheel under the control of said firststepping means.
 17. A timepiece as defined in claim 16 wherein saidco-operating members include a pawl on the side of said third wheelconfronting said first wheel, said biasing means comprising a springanchored to both said lever and said pawl.
 18. A timepiece as defined inclaim 15, further comprising stop means pivoted on said inner bracket inthe concave side of said second wheel facing said third wheel andresilient means normally holding said stop means in the path of severalprojections present on the confronting side of said third wheel forpreventing the latter from substantially overshooting an indexedindicating position thereof, a coacting projection in the concave sideof said second wheel being engageable with said stop means formomentarily deactivating same upon engagement with any of said severalprojections to permit the advance of said third wheel.
 19. A timepieceas defined in claim 1 wherein said selectors are a pair of peripherallytoothed drums, said transmission means being provided with a framesupporting said stepping means, further comprising a shaft on said frameparallel to said axis, a pair of setting wheels for said selectorsindependently rotatable on said shaft, and gear means positivelycoupling said setting wheels with said drums.
 20. A timepiece as definedin claim 19 wherein said first and second stepping means are a pair ofsliders reciprocably guided in said frame for parallel motion transverseto said axis, said sliders and said setting wheels projecting from theunderside of said frame at spaced-apart locations in coplanarrelationship to form a set of supporting legs therefor.